Continuous oxygen recorder



Nov. 5, 1935. c. PETTINGILL ET AL 2,019,371

CONTINUOUS OXYGEN RECORDER A Filed A ug. 26, 1953 Emmim'n essel for water v L Lty/zi 5222155 111 I MP far 50ZOZ n m M lit Jenni e J dent:

reaisi'arzce 28105 51042211 Eevezzmfile' a O 2 q mum GaZzmwarrzeZ'sr /\7 I a 5 INVENTORS MM Nov. 5,1935

CONTINUOUS OXYGEN RECORDER Clark Pettingill, Seal Beach, and Elmer J. Barlow.

, Long Beach, Calif.

Application August 20, 1933, Serial No. 686,948

BClalms.

This invention relates to the method and means of continuously recording the comparative amount of and variation of suspended vapors in a gaseous medium or light absorptive'matter 6 difl'used in a.liquid medium. The present embodiment refers more particularly to the method of continuously 1 recording the comparative amount and variation of the oxygen content of feed water for boilers, and apparatus for the i Purpose.

An object of the invention is to provide apparatus responsive to variations in the amount and intensity of light received from an established source which is varied by the variable light absorptive matter content of the medium being .examined and which will make a continuous rec- 0rd of the variations.

. The method contemplated in the present invention consists in passing radiant energy, such.

as light, from an established source, through a stream of water, adding to the water reagents which will react with the variable oxygen content of the water to change its radiation absorption quality and cause a definite resistance to the g5 passage of radiant energy from the source in accordance with the oxygen content of the water, again passing the radiant energy from the source through the solution and recording the variation in light absorption due tothe oxygen present in so the water and its reaction to the reagents. In making this method possible, means are provided whereby the variation in amount and intensity of light passing through the stream of water is.

caused to effect, through suitable light-sensitive devices, a balance of potentials between two electric circuits. Suitable means are provided whereby a continuous record is made of the extent to.

which the potentials are thrown out of balance by the variation in amount and intensity of the light directed to the light-sensitive .devices.

' The operative means employed and controlled by the variation between the potentials of the two circuits is also the operative means for making the record. The difference between the po- 5 tentials of the two circuits is made to effect the operation of the operating means of a suitable adjustable and regulatable resistance. Movement of the parts necessary to make the record and due to the unbalance of the potentials is-proportional to the variation in the amount'of oxygen in the feed water. Therefore a record is made of the movement of the parts due to the unbalance of the potentials between the circuits. More particularly, movement of the resistance 66 contact is coincident with movement of the recording stylus. A suitable motor is employed to move the parts to adjust the resistance and move the stylus. The motor is controlled by a circuit making galvanometer and a relay switch.

An object of the present invention is to provide 5 means whereby a continuous record may be made of the movement of the parts which is proportional to the amount of oxygen carried by the 1 water being examined. Another object is to produce a continuous record which will represent lo the proportional amount of oxygen in the water as it flows by the observation point, and which will show the variation in the amount of oxygen. Another obect is to employ and so arrange the parts that the oxygen present in the water being 15 examined is the control element in determining the movement of the stylus which makes the record. A still i'urtherobject is to provide an apparatus which is durable, reliable and not easily thrown out of adjustment.

Other objects and advantages will become more apparent from the following specification when considered in connection with the accompanying drawing, in which:

Fig. 1 is a diagrammatic representation of the g5 complete device showing means by which the water is presented before the light-sensitive de .vices both before and after the reagents "have been introduced, the circuits, the controlling devices, the operating means and the recording 30 a means.

Referring to the.drawing with more particularity, the lamp I, a suitable electric lamp, is used as a source of light for the examining ves sels 2 and 3. "A system is arranged through 5 which sample water may flow comprising, an in-' take pipe 4 which enters one end of the examining vessel 2, another pipe 5 which leads out oi' the opposite end of the examining vessel land enters the mixing chamber 6. This mixing cham- 4o Though many suitable reagents are known to those skilled in this art, the one which we have found very satisfactory and employed with the present apparatus consists of two primary solu-' tions combined in. the mixing chamber 8. 5

The first consists of: sugar 6 oz., p ogallic acid /2 oz., sulphuric acid, 2.5%, 1 oz., and water to make 32 oz.

Thesugar is used only to increase the specific gravity of the solution, so as to maintain a balanced condition. The sulphuric acid is used only to keep the pyrogallic acid from absorbing oxy- The s'odium'carbonate solution is fed in suili-,

cient quantity to neutralize the sulphuric acid in the first solutionand leave an excess to make the mixture alkaline. The pyrogallic acid in an alkaline solution has a great afllnity for oxygen and in combination with oxygen forms a brown bompound which discolors the feed water willcintly to affect the light absorptive condition of the feed water. The reagents are introduced in a suitable manner. as by a tube I, andso as to continuously supply a predetermined proportion and amount. The water then passes through the tube 8 to'the end oi the examining vessel 3 and out through the tube 3. The examining vessels 3 and 2 have transparent closures II and II- and I2 and I3 to admit oi light from the common source I passing through the vessels to fall upon the light-sensitive devices H and II, which will be more fully described as the description pro- 'ceeds.

If water is allowed'to flow through the examining vessels without physical or chemical change in the water between the two vessels 2 and 3. the

light absorptive condition oi the water will be the same in each vessel and an equal amount oi light will pass from the source I through the vessels to the light-sensitive devices II and II, no matter what the actual physical or chemical condition of the water may be: but it a change in the physical or chemical condition is brought about as the water passes through the mixing chamber 3 to make the water more turbid, or colored, or otherwise more light ahmrptiv'e, the amount andintensity of light through the examining vessels 2 and 3 will be unequal and the light-sensitive electric devices II and II will be aii'ected unequally.

' In the present embodiment and in the present drawing and description, the light-sensitive electric cells H and I! are light-sensitive generative electric cells and are the source of electric potentials in the circuits in which they are included. Such cells are well known to those skilled in this art and comprise a device in which the elements are so arranged that when exposed to the direct rays of light or suitable radiant energy electric energy is generated within the cell and proportional to the amount or intensity of the light received. In the circuit A, in which the cell II is included, is a resistance II. In the circuit B,

.in which the cell I4 is included. is an adjustable resistance l1, and an adjustable resistance I8 is included as a means by which the two cells may be balanced if unequal in efliciency. The'circuits A and B are opposed.

It, when light from the source is passed through the vessels 2 and 3 to the cells II and II, and

k the light absorptivecondition of the water in the vessels is'unequal, the cells It and I! will be aii'ected unequally. It more light passes through the vessel 2 than through the vessel 3, the'cell II will be more active than the cell II and generate more electricity resulting in a greater potential drop across the resistance l1 than across the resistance It.

A by-circuit C is provided connecting the positive side of the resistance ll with the arm-l0. or the resistance I1 and including a circuit making galvanometer 2|. The generating cells ll and I! are preferably of equal resistance, equal sensltiveness and equal generative value. and the resistances and H are of equal resistance value. when the drop across the resistances l8 and H is unequal and the potentials on either side of the circuit making galvanometer are unequal, the galvanometer will be affected thereby and its contact arm 2| will be moved to make a contact. v t

The circuit making galvanometer 20 may be] 01 any suitable type for the purpose and which is constructed to make and break circuits for the control of a relay switch. The type shown here to illustrate has a swinging contact arm 2| and two contact terminals 22 and 23, with either 1 oi which the arm 2i may make contact in its movement to bring about the closing of a circuit. a The contact terminal 22 may indicate a point to which the arm 2| may swing when the potential oi circuit 38 is greater than that of circuits A, and when the potential on that sideoi' the galvanometer including the lead 24 and that part oi the resistance I! included in the galvanometer circuit C at the moment is greater than on the other side of the galvanometer including the 2 lead 25.

A balance 01' potential across the galvanometer 20 may be made by moving the arm I! of the adjustable resistance II to include in the circuit C enough or the resistance I! to compensate for s the diflerence in potential across the galvanometer. Movement'oi' the arm l9 is-accomplished by means including, a threaded nut 28 on the threaded shaft 21, a reversing motor 28 which,

I through suitable speed reducing gears, drives 3 the shaft 21, a suitable source of energy 29, and a reversing switch 3|! which is a relay switch operable by remote control and may be '0! any standard type suitable for the purpose.

The motor 28, the relay switch 80 and the a galvanometer 20 are operably connected and associated. From the contact terminal 22 ot the galvanometer 20, a conductor 3| is carried to the relay switch 80, also a conductor 32 from the contact terminal 23, and a conductor 38 from the 4 contact arm 2|. when the arm 2| swings'to contact the terminal 22, a circuit through the conductors 3i and 33 is closed which operates the relay switch to close a circuit with the motor 23 to start the motor in the direction to 54 move the shaft 21 in the right direction.oi rotation to move the nut 28 and the resistance contact arm is to readjust the portion of the resistance I! included in the circuit C to bring about a balance oi potential across the galvanom- 55 eter 20. When this balance of potential is restored, the contact of the arm 2| and the terminal 22 be broken and, through the relay switch 30, the motor 28 will be deenergized and stopped. A reverse movement oi the motor 28, the nut 23 and the arm I! will be brought about it the contact is made between the arm 2| and the terminal 23 establishing a closed circuit through leads 32 and 33, and the adjustment oithe resistance i! will be in an opposite direc- 55 tion. Thus a balance 01' potential is-maintained worm the galvanometer 2|! by a movement oi the arm IQ of the adjustable resistance II to compensate for the diiIerence oi'potential, between the circuits A and B, or a difference in drop across the resistances l6 and I1. It is an object of the present invention to make a continuous record oi the movement of the arm is.

This is accomplished by attaching an arm 34 to a moving record sheet 86, by which means a record, indicated as I1, is made upon the moving sheet 38.

When a contact is once made between the arm 2| and one of the terminals 22 or 23, the contact will not be broken until the balance of potential across the galvanometer has been restored, and so long as a contact is made the motor will continue to move the nut 26 and the arm ll of the resistance ll. Therefore the movement 01' the arm is is proportional to the amount the potentials across the galvanometer are out 01' balance, and this is an indication oi the ratio or proportional difference oi potential between the circuits A and B, or between the drop across the resistance II and the resistance II. This is also a measure of the ratio or proportional difierence between the amount of energy generated by the cell II and the cell l5. As the generative value of the cells H and I5 depends upon the amount of light which falls upon the cells, and is proportional thereto, the movement oi the arm I! is proportional to the ratio or proportional difference between the amount 01' light which is allowed to pass through the vessels 2 and 3. It is also a measure of the extent to which the water in one vessel is light absorptive as compared to the water in the other vessel. As the light absorptiveness of the water in one of the vessels is directly dependent upon the amount of oxygen in the water and its reaction to the reagents introduced between the two vessels, the operation of the cells I! and IS, the consequent difl'erence in potential between the circuits A and B, the difference in potential across the galvanometer 2D, and the movement of the arm I! are all dependent upon and pro portional to the amount of oxygen in the water and its reaction to the reagents introduced between the two examining vessels. Therefore the movement of the stylus 35 and the record 31 made by it will be proportional to the amount of oxygen in the water, and as the record sheet moves, the record 31 will be a continuous record of the variations in amount or oxygen in the water as it flows through the examining vessels.

The adjustable resistance i8 is introduced as a means for balancing the output of the cells I I and i5, should they be unequal in generative efficiency, but other well known means may be employed for the purpose. The lamp I may be adjusted to bring about the same result by distribution oi the light, or an adjustable screen which will partially screen one of the cells. There is variation in the amount of light which emanates from the opposite sides of otherwise standard lamps, and the lamp must be adjusted and arranged accordingly.

The parts employed in the construction of our invention and the distribution of the parts may be modified, but the description oi the present embodiment conveys the operation of the device in attaining the objects sought and the relation and distribution of the parts.

Having thus described our invention, what we claim is:

1. An apparatus for making a continuous record of the oxygen content of flowing water comprising, two electric circuits opposed as to potentials, in one circuit a light-sensitive electric generative device whereby a potential drop is maintained across a resistance in that circuit, in the other circuit a light-sensitive electric generative device whereby a potential drop is maintained across another resistance, a source of light common to said light-sensitive devices, means whereby water may be interposed between said source 01' light and said light-sensitive devices whereby the potentials in said circuits are affected by. a partial absorption of the light directed to said 5 light-sensitive devices, means controlled by the potentials in said circuits whereby an adjustable resistance is adjusted, and means whereby a continuous record is made of the changes in adJustment of said adjustable resistance. 10

2. An apparatus for making a continuous record of the oxygen content of flowing water comprising, two electric circuits opposed as to potentials, a light-sensitive electric generative device in each of said circuits, each of said de- 16 vices responsive to the amount oi! light absorptive substance carried in suspension in the water passing before said devices, a resistance in each oi. said circuits, a source 01' light common to said light-sensitive devices, means whereby water 20 may be interposed between the source of light and said light-sensitive devices whereby the potentials in said circuits are affected by the partial absorption of the light directed to said lightsensitive devices, a recording means, a regulat- 25 able resistance, and means controlled by the potentials in said circuits for regulating said regulatable resistance and making a continuous record directly with variations oi! the light ab sorbed.

3. An apparatus for making a continuous record of the oxygen content of flowing water comprising, two examining vessels constructed and arranged to allow a stream oi water to flow through the vessels consecutively, means for in- 35 troducing reagents into the water between the vessels to effect a change in the lightabsorptive quality of the water due to the reaction of oxygen present in the water, a source of light common to said vessels, two light-sensitive electric 40 generative devices constructed and arranged to receive light through said vessels and maintain electric potentials in two opposed circuits, and means whereby a continuous record is made of the ratio between the potentials of the two ch- 46 cuits including, a circuit making galvanometer,

a relay switch operably connected therewith and a-motor.

4. An apparatus for making a continuous record of the oxygen content of flowing water com- 50 prising, two examining vesels constructed and arranged to allow a stream of water to flow through the vessels consecutively, means for introducing reagents into the water between the vessels to efl'ect a change in the light absorptive quality of the water due to the reaction of oxygen present in the water, a source oi light common to said vessels, two light-sensitive electric generative devices constructed and arranged to receive light through said vessels and maintain electric potentials in two opposed circuits, a re cording means including, a motor, and means whereby the operation of said motor is controlled by and in accordance with the oxygen in the water flowing through said vessels.

5. An apparatus for making a continuous record of the oxygen content of flowing water comprising, two examining vessels constructed and arranged to allow a stream of water to flow through the vessels consecutively, means for introducing reagents into the water between the vessels to effect a change in the light absorptive quality of the water due to the reaction of the oxygen present in the water, a source of light common to said vessels, two light-sensitive electric generative devices constructed and arranged to receive light through said vessels and maintain electric potentials in two opposed circuits, a recording means including.-an adjustable resistance, a recording stylus, a motor operably connected with said adjustable resistance and said recording stylus. and means whereby the operation of said motor is controlled by and in accordance with the oxygen in the water flowing through said vessels.

6. The method or making a continuous record of the amount oi oxygen present in flowing water which consists in, passing the water through a transparent vessel, introducing suitable reagents such as pyrogallic acid and sodium carbonate into the water whereby the light absorptive quality of the water is changed by reaction of the oxygen to the reagents, passing the water through a second transparent vessel, causing light i'rom a common source to pass through said vessels, causing the light which passes through said vessels to fall upon light-sensitive electric generative cells whereby potentials are maintained in opposed circuits, and continuously recording the ratio of variation in potentials between the circuits.

CLARK PE'I'IINGJLL. ELMER J. HARLOW. 

